Denmark, Sweden, and Germany discuss boundaries. Representatives will meet in Brussels to coordinate efforts to control the flow of migrants through Europe, after recent border closures have made travel more complicated for commuters.

Taiwan and Japan discuss so-called comfort women. After Japanese prime minister Shinzo Abe formally apologized to South Korean women forced to work in Japan’s wartime brothels, officials will hold negotiations on behalf of Taiwanese victims.

Charlie Hebdo marks a painful anniversary. One year after extremists attacked the Paris office of the satirical magazine and killed 12 people, it will print 1 million copies of a special issue. The cover features a murderous God along with the words, “One year on: the assassin still at large.”

While you were sleeping

North Korea claimed to have detonated a hydrogen bomb. Official media said the military tested the bomb, while earthquake sensors in neighboring countries detected tremors of up to magnitude 5.1 from the apparent test site. South Korea’s government is holding an emergency meeting.

Apple plans to slow down its iPhone production. The tech giant plans to cut the number of iPhones it produces in Japan and South Korea by 30% this quarter, according to Nikkei. The cutbacks are due to an oversupply of the iPhone 6s and 6s Plus models; Apple’s share price dropped by 2.8%.

Hundreds protested sex attacks in Germany. Protestors gathered to demand action following reports that scores of women were robbed and sexually assaulted on New Year’s Eve, mainly in the city of Cologne. Witnesses and police said that the suspects were of Arab or North African appearance, which could fuel anti-refugee sentiment.

Samsung expanded mobile payments. The South Korean smartphone maker’s payments technology will be available in Singapore, Australia, and Brazil. Samsung is competing with Apple’s mobile payments system around the world.

Quartz obsession interlude

Jake Flanagin on why we can’t get enough of true crime shows. “Instead of fetishizing the criminal and the crime, Serial and Making a Murderer take a long, hard look at the contexts in which such atrocities arise, how we as a society deal with them, and whether our methods of delivering justice are as sound as they are purported to be.” Read more here.

Matters of debate

Twitter would be right to expand its character limit from 140 to 10,000. Here’s why—in 10,000 characters.